Why enroll

We will see live examples where we shall calculate LMTD and understand its importance with following

Images of tube side fouling

Images of shell side fouling

Your instructor

Process Engineering World

Is this course for you?

You should take this if

You work in Oil & Gas Upstream or Pharmaceutical & Healthcare
You're a Chemical & Process professional
You prefer live, instructor-led training with Q&A

You should skip if

You need a different specialisation outside Chemical & Process
You need fully self-paced, on-demand content

Course details

As a chemical engineer, understand the operating principles of heat exchangers and how to tackle on site problems in plants

Course suitable for

Opportunities that await you!

Career opportunities

Certifications

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Training details

This is a live course that has a scheduled start date.

✎ Where this fits — what comes before, what comes next

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Questions and Answers

Q: You're on night shift and searching "LMTD heat exchanger calculation countercurrent example with units" after the DCS shows a duty mismatch. A countercurrent shell-and-tube exchanger cools oil from 160°C to 90°C using water entering at 30°C and leaving at 55°C. What LMTD should you be using in the duty check?

A: The hard boundary here is the log term. ΔT_hot-in/cold-out is 160−55 = 105°C, while ΔT_hot-out/cold-in is 90−30 = 60°C. LMTD = (105−60)/ln(105/60) ≈ 71°C. Arithmetic averaging ignores the logarithmic temperature driving force, and the correction factor comes later, not inside the base LMTD.

Q: You're Googling "back of envelope heat exchanger area estimate crude preheat" while two senior engineers argue over fouling. A crude stream at 50,000 kg/h is heated from 40°C to 120°C using hot product. Cp ≈ 2.2 kJ/kg·K and you expect an overall U of 250 W/m²·K with a 30°C LMTD. What area order-of-magnitude makes sense?

A: The number that bites is the duty scale. Q ≈ 50,000/3600×2,200×80 ≈ 2.4 MW. Area ≈ 2.4×10⁶ /(250×30) ≈ 320 m², so a few hundred square metres fits. Dropping the hour-to-second conversion or misusing the sensible rise as LMTD skews the estimate by an order.

Q: Your lead pings you with "API 660 minimum fouling resistance requirement shell and tube" after a vendor datasheet looks optimistic. For refinery service exchangers, why does API 660 mandate minimum fouling factors even when the licensor claims clean service?

A: The non-negotiable limit is end-of-run performance. API 660 assumes refinery services foul unpredictably, and the exchanger still has to meet duty before turnaround. ASME VIII governs pressure integrity, not heat transfer, and TEMA class affects mechanical robustness, not mandatory fouling allowances.

Q: You're searching "heat exchanger tube material chloride SCC cooling water" after spotting hairline leaks. Cooling water at 60°C contains 800 ppm chlorides with intermittent oxygen ingress. Which degradation mechanism dominates for austenitic stainless tubes?

A: The threshold here is chloride plus oxygen at moderate temperature. Austenitic SS fails by SCC under tensile stress long before uniform wall loss appears. Sulfidation and naphthenic acid attack need sulfur species or much higher metal temperatures.